Speaker help for a newbie.

[Electronic M]

Originally Posted by Phil

Perhaps I am reading the schematic incorrectly but it appears to me there is a jumper on the plug taking B+ to the Ct of the output transformer. If that is true then the current for the output stage is not going through the choke.

It looks like it's on the output side (farthest end from the rectifier) of the choke so the audio trans current would be going through the choke... Unless I'm reading it wrong on my phone screen.

[old_coot88]

If current to the output xfmr were not going thru the choke (field coil), the field would be very weak. That's cuz the output draws more B+ current than (probably) all the other stages combined.. thus maximally energizing the speaker field. Tryin' to sound all fancy-shmancy.

[Phil]

Originally Posted by old_coot88

If current to the output xfmr were not going thru the choke (field coil), the field would be very weak. That's cuz the output draws more B+ current than (probably) all the other stages combined.. thus maximally energizing the speaker field. Tryin' to sound all fancy-shmancy.

Quite true! Obviously, I'm not reading the schematic correctly on my phone.

A choke of that current is going to be expensive so he might want to replace it with a resistor and put a larger cap after the resistor. I wouldn't increase the 40 mfd cap as it is much to large for the rectifier anyway (based on tube data sheets) and filtering will be better with the RC circuit.